12v USB-C Power Delivery Plug

Comparing voltage readings

There is definitely a craze going on in the amateur radio community with regards to USB-C PD.

What is USB-C PD and why are hams suddenly interested?

What is USB-C PD?

USB-C PD stands for USB-C (the ubiquitous port showing up on everything) and PD stands for Power Delivery. The PD part is intriguing because it enables higher voltages to be achieved from the port. The spec talks about 5, 9, 12, 15, and 20 volts being available. As hams, we’re interested in the 12v and 15v aspect of this PD spec since our life revolves around them.

Why Do Hams Care about USB-C PD?

A regular USB port on your computer or wall wart only output 5 volts at 1-2 amps. In order to do something useful (like charge your Yaesu radio) with it, you’d have to step up the voltage to what the radio needs to charge the battery. For example, my FT-5D has a 4.0mm x 1.7mm barrel connector marked “EXT DC IN JACK” on the side that can charge the battery. My manual says we have to use Yaesu products to do this but we’re hams, right? In the specifications section it says we can supply 10.5 -16v DC then it should charge the battery. That means if we buy barrel connectors with the correct trigger voltage chip, then we can throw away all of our HT chargers!

Here’s where the PD part comes in. The PD spec allows a USB-C PD port to output 5v, 12v, 15v, 20v.

So what? There are a lot of batteries that you can buy that claim to have USB-C PD ports.

Notice above that I said “allows”. Turns out some hams are noticing that a portable phone charging battery with USB-C PD ports that they tried can’t power or charge their ham radio devices (which usually require 13.6 +/- 15% which equals anywhere from 11.56v – 15.64v). It’s because their USB-C PD enabled battery ports probably skip over those voltages so if they’re using USB-C PD ports that “trigger” those voltages via the use of electronics, the USB-C PD port won’t supply 12 or 15 volts.

But wait – does this mean you have to find a portable battery that ham have certified can output 12 or 15 volts? No!

We’re hams! We can make our own and make it better!

Holy grail of USB-C PD chargers for Amateur Radio

I found this OSB-C PD charger which I think works great and gives great feedback that us hams require.

USB-C PD charging at 15v 1.22 amps
Triggered at 15 volts and charging a Surface 4 laptop at 1.22 Amps

Some features that I find useful:
0. Works off a typical ham radio battery. In my case this is my trusty desktop ham radio workhorse – a TalentCell 12000 mAh LiFePO4 battery. The device shows 13.4 volts which is in the neighborhood of what my every day voltage meter shows.

Comparing voltage readings Charger reading 13.4 volts and meter reading 13.23 volts

1. Digital display of input voltage which automatically switches to amps when supplying current. When its done charging or not supplying current, it switches back to showing the input voltage. Very convenient.

2. Digital display shows the triggered output voltage. This is key!

3. Dust cover.

4. On/Off switch. Note when its off it still draws a little power to detect when you pressed the switch, much like my Yaesu FT-5D.

5. Inline fuse (250v / 10a).

6. Metal body. I think the mounting threads will double as cooling fins.

I’ve already charged a keyboard, mouse, Surface Pro 4 (using a USB-C trigger dongle).

It’s interesting to see what voltage and current each device charging negotiates by itself. For example, when I have my Surface 4 USB-C PD charging trigger, I can see it negotiated 15v – even without a load on it. Pretty neat.

Surface Pro USB-C Trigger Surface Pro USB-C trigger at 15 volts

The digital display can be used with triggers to see if they’re working according to spec. For example, I’ve read about people buying 12v triggers for their Yaesu’s only to find out they triggered 15v, not 12v. It’s not the end of the world since 15v won’t let the magic smoke out but why not be sure?

I’m also using the USB-C PD charger to see if there are voltage trigger chips inside a particular USB or USB-C plug to trigger any particular voltage.

Next steps will be removing the ring connectors off the ends and add Anderson PowerPole Connectors on the ends so that I can connect them to any of my ham radio batteries, including some smaller Bioenno’s that have PowerPoles on them already!

Now, it does sound a little silly to connect this USB device to a 12v battery to only get out 12v using a trigger, wasting a little in the conversion process. The magic is that you effectively have a step up converter that enables you to get rid of some wall warts.

Say I wanted to charge my marine radio (A Standard Horizon/Yaesu HX 890) on its cradle at 15v instead of 12v, which the spec says I can. At that higher voltage, it might charge faster (I haven’t tested this). All I need is the proper barrel connector that triggers 15v (maybe something like this one that I’m eyeing) and I’d be all set!


Give it a try and let me know how it goes!

73,

KV0N

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